Last Rites

Lead Cristina to the yellow marker on your map by turning first east and then south. Cristina can't follow you onto rooftops so stick to the ground, and avoid confrontations. When you reach the waypoint, you'll have to beat up a guard. Again, you've got no weapons, just your fists, so target the guy and mash the attack button.

Another waypoint shows up. Lead Cristina to it, again avoiding rooftops and brawls with guards. The two of you stop just shy of three bodies that Ezio needs to move. Hop to a nearby balcony and take a leap of faith into the straw south of it to avoid detection, then pick up the bodies and carry them down to the boat on the docks. Each time you come up to the bodies, watch for patrolling guards. If you get caught, you can get away by jumping into the water and swimming behind a boat. The mission ends when you've transported all three bodies to the boat.